Basically it looks like this.
The rope goes from the object to a caribiner that is hooked into the anchor. Then it goes back down to where a prussik and a caribiner have been hooked to the rope going to the object. Then you take the rope through the caribiner, back towards the anchor.
To make it easier one could use pulleys instead of caribiners. For safety the one should use two opposite and opposed caribiners at each point, just as if your were setting up an anchor.
It is also possible to add another prussik to capture the progress,
or to use a one way pulley at the anchor.
It is also possible to add another line to the Z to increase the advantage from 3:1 to 5:1.